Devices may connect over a wireless network to communicate with both local and remote devices. For example, a wireless network includes a Wi-Fi or wireless local area network. In that manner, network resources (e.g., internet) are made available by connecting to the wireless network, such as through a wireless network access point.
Wi-Fi scans are used to determine the availability of wireless access points to a device. When a scan is triggered, a Wi-Fi chip in the device switches across the regulated channels of the Wi-Fi spectrum. If the device is already associated with or connected to an access point on a particular channel (e.g., the home channel), the Wi-Fi radio is tuned out of that channel momentarily to perform a complete and full scan. The Wi-Fi chip can periodically return to the home channel to transmit/receive any buffered frames in between scans.
However, Wi-Fi scans on consumer mobile devices are expensive in terms of Wi-Fi chip power consumption and time for which the radio is off-channel and unavailable for transferring data. As a result, the user experience is less than satisfactory due to jitter introduced when performing scans, and the drainage of battery power. In particular, when tuning the Wi-Fi radio to a different channel from the home channel downstream frames intended for the device are buffered at the access point, and upstream frames to be sent out from the device are also buffered in the device Wi-Fi firmware. The buffering of frames causes a sudden burst of packets when the device switches back to the home channel, which leads to potential packet loss to and from the device. Further, buffering also introduces undesirable delays in packet transmission which introduces jitter in latency-sensitive real-time traffic like audio/video data received by the device. That is, performing scans while amidst a streaming session at the device can disrupt packet flow and introduce jitter, such that audio/visual synchronization issues arise, and video stuttering may occur. Further, when performing scans, the continuous switching of channels and sending of probes results in increased power consumption by the Wi-Fi chip. Periodic scanning could potentially lead to battery drain in the device.
It is desirable to ensure a high quality user experience when performing scans at a device.